Electronic mail (“e-mail”) messages may be encoded using one of a number of known protocols. Some of these protocols, such as Secure Multiple Internet Mail Extensions (“S/MIME”) for example, rely on public and private encryption keys to provide confidentiality and integrity, and on a Public Key Infrastructure (PKI) to communicate information that provides authentication and authorization. Data encrypted using a private key of a private key/public key pair can only be decrypted using the corresponding public key of the pair, and vice-versa. The authenticity of public keys used in the encoding of messages may be validated using certificates. In particular, if a user of a computing device wishes to encrypt a message before the message is sent to a particular individual, the user will require a certificate for that individual. That certificate will typically comprise the public key of the individual, as well as other identification-related information. Similarly, if a user of a computing device receives a message that has been digitally signed by a particular individual, the user will require the proper certificate (comprising a public key) for that individual if the user wishes to verify the digital signature on the message. In some variant systems, a Pretty Good Privacy (PGP) key or some other object that serves to bind the sender's identity and a public key would be required to verify the digital signature of a message.
Typically, in known e-mail applications, if the certificate that is required to verify the digital signature of a signed message received by a user is not stored at the user's computing device, the user may attempt to search for and retrieve the requisite certificate (e.g. from a remote certificate server) by manually opening a different application to initiate the search and retrieval of the certificate. The user may then initiate a verification of the digital signature with the retrieved certificate through the e-mail application.
Furthermore, even if the certificate required to verify the digital signature of a signed message received by a user is already stored on the user's computing device, the user may wish to determine an up-to-date revocation status for that certificate. Typically, in known e-mail applications, the user may initiate a verification of the revocation status of certificates in order to retrieve such information manually, by identifying a specific certificate and selecting a corresponding menu option, for example.